Drafting pen



vMay s, 194s.

H. H. BLAKE, JR

DRAFTING PEN Filed Oct. 16, 1943 ammi Nall@ IN V EN TOR.,

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-mwmll w.. M m l A Patented May 8, 1945 4UNITED STATES PATENT QFFICE DRAFTING PEN Hal-01d H. Blake, Jr., Burlingame, Calif.

Application October 16, 1943, Serial No. 506,507

(cl. 12o-48) 16 Claims. l

The present invention relates to improvements in a drafting pen, and is intended to carry forward certain ideas and improvements disclosed in my Patent No. 2,231,246 of February 1v1, 1941.

More particularly it is proposed to provide a pen of the character described that may be conveniently used for drawing lines and for lettering, so as to make it unnecessary for the draftsman to shift from one pen to another for the purposes aforesaid. 8

A further object of my invention is to provide a pen of lthe character described that presents a smooth and streamlined surface from one end to the other, substantially of fountain pen thickness, tapering gradually toward the point, and in which the adjusting means are arranged inside the pen, whereby theouter face is left entirely unobstructed.

A still further object of my inventionvis to provide a novel arrangement of pen-point sections lending itself particularly to the carrying out of the main idea of my invention, and a novel operating means for spreading the sections adapted for control bby a cap at the upper end of the pen.

And finally it is proposed to simplify the construction of the pen previously described, wherebythe front portion of the pen may be made in one piece and the cap is firmly anchored against removal.

Further objects and advantages of my invention will appear as the specification proceeds, and the novel features of my pen will be fully dened in the claims hereto attached.

The preferred form of my invention is illustrated in the accompany drawing in which:

Figure 1 shows a side elevation of my combination ruling and lettering pen;

Figure 2, a longitudinal section taken along line 2-2 of Figure 1, the section being shown on an enlarged scale; and

Figure 3, a transverse section taken along line 3 3 of Figure 2, drawn to a still larger scale.

While I have shown only the preferred form of my invention, I wish to have it understood that various changes or modifications may be made within the scope of the'claims hereto attached, without departing from the spirit of the invention.

Referring to the drawing in detail, my pen I comprises in its principal features a point 2, a stem 3, a cap 4, a sleeve 5 for holding the cap to the stern, and an operating member 6 entirely concealed within the pen.

The pen point comprises a base 'l having twol point sectionsk 8 projecting forwardly therefrom may turn for spreading the point sections.

and having a reduced threaded extension 9 proat I0. 0

Near the base the pointsections are formedv with cavities I I which provide weakened portions I2 on which the outer parts of the points The material of the point has sufcient elasticity to bring the point sections together again when the expanding force is withdrawn.

The cavities I I extend straight across the point sections, and are curved along the length of the pen as shown in Figure 2, the curvatures being drawn substantially to the arc of a circle.

The inner faces of the point sections are flat and run parallel to one another for a short di'stance beginning at the base, as at I5, to a point intermediate of the weakened portion, and from there they taper toward one another until they come to the point I0, where they bear upon one another under slight pressure to form an ink well.

The outer surfaces of the point sections may be finished to the form shown and the inner end of the pen point be completed by drilling a cylindrical bore i6 into the pen point from the other end up to the beginning of the slot and by threading the reduced extension 9.

The stem 3 is hollow throughout the length thereof and has an internal thread I7 fitting on the reduced extension of the pen point. It is formedwith an internal shoulder I8 and may have a metallic ring I9 bearing on the shoulder from the inner end. l l

The sleeve 5 is formed with a head 20 adapted to bear on the ring I9, with the sleeve projecting rearwardly from the stem. The cap 4 has a reduced front end 2| telescoping into the rear end of the stem with freedom of turning movement and is formed with a bore 22 adapted to receive the rear end of the sleeve 3.

The telescoping engagement may be omitted, and in that case the sleeve 5 alone would be relied on for holding the cap to the stem.

A ring 23 may be introduced between the stem and the cap. The latter is anchored to the sleeve by a cross-pin 2li whereby the cap and the stem are firmly held in assembled relation.

The operating member 6 is in the form of a rod having its rear end threaded into the rear portion of the sleeve 5, as at 25, an intermediate portion extending through the stem and a front portion projecting into the pen point.

'Ifhe front end of the rod is formed with a head or plunger 25 flattened on opposite sides to loosely fit between the at faces of the point sections, but suiiciently wide, as shown in Figure 3, to prevent rotation within the slot.

When retracted, as in Figure 2,' the head bears against the material of the base at the inner end of the slot whereby further `retraction is prevented. v l 4 l Y The head has suiicient clearancein the rear end of the slot to allow itl to enter between out forcing the sections apart, as shown in Figure 2.

Since the rod is thus held against turning movement, rotation of the cap in one direction or the other will advance or retract `the rod through the threads 25. As the rod advances, the head serves as a wedge to spread the point sections apart to increase the thickness of a line to be drawn by the pen, and as the rod is retracted, it will allow the point sections to move toward one another vuntil they` co-me in contact.

The rod may have a nut 2'! threaded thereon .to bear on the rear end of the base for limiting the extent of the forward movement of the rod.

The method of assembling my pen is Very simple: The rod S is preferably made a permanent part ofthe pen point so as to form a unit therewith. The stem 3y and the cap 4 may be readily united into a second unit by means of the sleeve 5. The two units may then be connectedl` by threading the operating member 6 into the sleeve 5 and thepen point into the'stem. The head 25 has sufhcient lengthwise movement in the slot to the two point sections for a certain distance with- ,tened to hold the said members against rotation,

and the said members having means adjustable thereon and cooperable with the base for limit- ,ing the advance movement ofv said member.

6. A drafting pen comprising a base having a pair of complementary pen point sections procompensate for the diiference in the two threads.k v

I claim:

1.`A drafting pen comprising a base having a4 pair of complementary pen point sections projecting therefrom, the said sections having respective weakenedportions near thebase and tions to form a tapered ink. well whereby ther point sections may be turned symmetrically on the weakened portions for spreading operations.

3. A drafting'pen comprising a base having a pair of. complementary. pen point sections projecting therefrom, the said sections having weak-Y ened lportions near the base and being bent toward one another at said portions to formV a tapered ink well, and having means movable therefrom for spreading the'sections apart.

4. A drafting pen comprising a base having a pair of complementary pen point sections projecting therefrom, the said sections having cavities in the outer faces thereof near the base to provide weakened portions and being bent toward one lanother at the weakend portions to form a tapered ink well, and having means movable therebetween vfor spreading the sections apart.

5. A drafting pen comprising a` base having a pair of complementary pen point sections projecting therefrom, the 'pointl sections being shaped to form a tapered ink well therebetween,

jecting fromthe front thereof, the point sections being shaped to form a tapered ink well therebetween, a hollow stem secured upon the rear end of the base and having a shoulder therein, asleeve bearing on said shoulder and extending rearwardly beyond the stem, a cap revolvably attached tothe rearend ofthe stein and anchored tothe sleeve for holding the cap against removal, andv an operating member having a rear end threaded into the sleeve and a front end projectrear end ,of the base and having a shoulder therein, a sleeve bearing on said shoulder and extending rearwardly beyond the stem, a cap revolvably attached to the rear end of the stem and anchored to the sleeve for holding the cap against removaLand an operating member having a rear end threaded into the sleeve and a front end projecting into the space between the point sections for separating the latter when the cap is turned, the front end of the operating member being flattened to hold the same against rotation. Y

8. A drafting pen comprising a base having a pair of complementary pen point sections projecting from the front end thereof, the point sections being shaped to form a tapered ink well therebetween, a" hollow stem secured upon the rear end of the base and having a shoulder therein, a sleeve bearing on said shoulder and extending rearwardly beyond the stem, a cap revolvably attached to the rear end of the stem and anchored to the sleeve for holding the cap against removal, and an operating member having a rear 'end threaded into the sleeve and a front end projecting into the space between the point sections for separating the latter when the capv is turned, the front end of the operating member being flattened to hold the same against rotation,and the said' member having means adjustable thereon and cooperable with the base for limiting the advance movement of the `member. v

9. A drafting pen comprising a base having a pairof complementary pen point sections projecting therefrom, the point sections being shaped to form a tapered ink well therebetween, and tensioned to normaily bear on one another at the tips, a stem secured upon the base opposite the point sections, a cap revolvable upon the free end of the stem, a plunger movable longitudinally between the point sections vfor spreading the same when the plunger is advanced, and means operable by the cap for advancing the plunger.

10.A drafting pen comprising a base having a pair of complementary pen point sections pro- `iecting therefrom, the point sections being shaped to form a tapered ink well therebetween, and tensioned to normally bear onone another at the tips, a stem secured upon the base opposite the point sections, a cap revolvable upon the free end of the stem, a plunger movable longitudinally between the point sections for spreading the same when the plunger is advanced, means operable by the cap for advancing the plunger, and means for limiting the forward movement of the plunger.

ll. A drafting pen comprising a base having a pair of complementary pen point sections projecting therefrom, the point sections being shaped to form a tapered ink well therebetween, and tensioned to normally bear on one another at the tips, a stem secured upon the base opposite the point sections, a cap revolvable upon the free end of the stem, a plunger movable longitudinally between the point sections for spreading the same when the plunger is advanced, means operable by the cap for advancing-the plunger, and means for limiting the rearward movement of the plunger.

1 2. A drafting pen comprising a base having a pair of complementary pen point sections projecting therefrom. the point sections being shaped to form a tapered ink well therebetween and tensioned to normally bear upon one another at the tips, a stem secured upon the base opposite the point sections, a cap revolvable upon the free en d oi the stem, means for locking the cap to the stem, a plunger movable longitudinally between the point sections for spreading the same, and means operable by the cap for moving the plunger.

13. A drafting pen comprising a base having a pair of complementary pen point sections projecting therefrom,the point sections being shaped to form a'tapered ink well therebetween and tensioned to normally bear upon one another at the tips, a stem secured upon the base opposite the point sections, a cap revo-lvable upon the free end of the stein, means for locking the cap to the Stem, a plungerl movable longitudinally between the point sections for spreading the same, and means operable by the cap for moving the plunger, the latter means being connected into the locking means.l `14. In a drafting pen, a substantially rigidonepiece pen point comprising a rigid annular base having a pair of symmetrical pen point sections formed integrally'therewith and projecting therefrom, the sections having at and straight inner faces and curved outer faces tapering from the base toward the tips, and being bent toward one another to come to a point at the tips and tensioned to exert pressure upon one another'at the tips. f

l5. A drafting pen comprising a base having a pair of complementary pen point sections projecting therefrom, the point sections being shaped to form a tapered ink well and being tensioned to bear on one another at the tips, and a plunger movable between the point sections for forcing the same apart when the plunger is advanced.

16. In a drafting pen, a hollow stem having a shoulder therein, a cap revolvable on the rear end of the stem, a sleeve inside the stern and the cap and having a head bearingvon the shoulder, and means for anchoring the sleeve to the cap, the sleeve having an inner thread to serve as an operating means when the cap is revolved.

HAROLD H. BLAKE, JR. 

